Feds take aim at fish-eating cormorants
January 10, 2002
BY ERIC SHARP
Detroit Free Press
January 17, 2001
Some years ago, a biologist told me his fish hatchery
had a federal permit to kill 50 of the hundreds of sea
gulls that raided the place and ate tens of thousands
of fish each year.
Just inside the door were a 12-gauge shotgun
and a case of about 1,000 shotgun shells. I joked that if
they needed all those shells to kill 50 sea gulls, the hatchery
workers must be pretty poor shots.
The biologist smiled and said, "Oh, we're good shots.
We just don't count very well."
That incident came to mind when I received a copy of
a recent U.S. Fish and Wildlife Service draft environmental
impact statement on the problems that double-crested cormorants
are causing on the Great Lakes and other waters.
Buried in a mass of bureau-speak is an admission that
the big, fish-eating birds are having a deleterious effect
on food and game-fish populations in some areas. The feds
also admit that Michigan and other Great Lakes states
should be allowed to reduce the cormorant numbers in places
where they are doing damage.
Individuals wouldn't be allowed to kill them, but state,
federal and Indian tribe wildlife officers would get permits
to reduce cormorant numbers in places like northern Lake
Huron and Beaver Island in Lake Michigan.
The double-crested cormorant is a large, black, hook-billed
bird. It is an effective underwater predator that eats
about a pound of fish a day and prefers them in the five-
to eight-inch range. How many cormorants live on the Great
Lakes is open to question. The Fish and Wildlife Service
says there were only 89 nesting pairs on the lakes in
1970, but that number had soared to 93,000 pairs by 1997.
For every nesting pair there are an average of two more
young adult birds that don't nest, putting the 1997 total
at about 372,000.
The average annual population growth since 1997 has
been 7.9 percent, a big slowdown from the 29 percent rate
of the 1980s. Using that figure, we get a 2001 Great Lakes
cormorant population of about 504,000. At the same time,
the Fish and Wildlife Service says that about 1.2 million
of the nation's 2 million double-crested cormorants live
on the Great Lakes and in central Canada.
People who oppose killing cormorants say 98 percent
of the fish they eat aren't species that humans use for
food or sport. But that ignores the fact that if you have
enough cormorants, even 1 percent is a lot, and in some
places they take a far bigger percentage of game fish
than the average would suggest.
If we use a rough figure of 500,000 cormorants on the
Great Lakes, they would eat more than 75 million pounds
of fish in the five to six months they spend here. That
seems like a lot, but it's only a tiny fraction of the
fish consumed by salmon, bass, walleyes and other fish.
But if you get a large concentration of cormorants in
one small area, like the 10,000 estimated to nest around
Beaver Island, you can run into problems with sportfish
The Beaver Island area, northwest of Petoskey, used
to offer spectacular fishing for smallmouth bass, but
a couple of years ago residents and visitors noticed an
odd and disturbing phenomenon: You still could catch big
smallmouths, 12 inches or longer, but smallies under 10
inches were rare.
A 2-year-old smallmouth bass in Lake Michigan is about
six inches long and six ounces in weight, the size that
cormorants love. You don't have to be a rocket scientist
to figure out that 10,000 cormorants feeding around the
islands soon will make a major dent in the bass population.
If each bird ate only two six-inch bass a week, by the
end of the summer they would have downed about 500,000
of the undersized game fish.
Something similar happened around the Les Cheneaux Islands
in northern Lake Huron, where perch fishing, the butter
on the bread of the tourism industry, has fallen off dramatically.
Locals have complained for years that a huge increase
in double-crested cormorants was responsible.
People I know in the Fish and Wildlife Service say the
big problem in dealing with cormorants, or any other animal
that becomes a nuisance, is that the agency bends to pressure
from animal rights groups and others who oppose killing
wildlife. The groups are small but well organized, while
anglers are not. (People usually become anglers to get
away from their organized daily lives.)
It's no accident that the only groups allowed federal
permits to kill cormorants are state fish hatcheries and
commercial fish farms. They also are well organized, have
political clout and can put even more pressure on the
Fish and Wildlife Service than those who want to protect
It would be a mistake to try to blame cormorants for
all the ills that befall sportfishing. We humans are responsible
for far more damage to the Great Lakes than cormorants
could ever do. But it makes sense for the feds to allow
the states and tribes to kill a relatively small number
of an abundant exotic species and see if it makes a difference
in the fish populations the states and tribes are trying
The Fish and Wildlife Service held a public meeting
on the cormorant issue Tuesday night in Mackinaw City,
a time of year when the town's population is at a low
ebb. On the off-chance you didn't have the time to drive
five hours each way from Detroit on a weekday evening,
you have until Tuesday to send written comments on the
cormorant debate by e-mail to email@example.com,
by fax to 703-358-2272, or by mail to Division of Migratory
Bird Management, U.S. Fish and Wildlife Service, 4401
N. Fairfax Drive, Room 634, Arlington, Va. 22203.